Question

我正在尝试进行阻止调用以检索PDF文件，但每当我尝试使用返回的有效负载（包括发送它）时都会抛出错误。

错误是＆＃34;在关闭的流＆＃34;上尝试读取，我认为它正在发生，因为只有在需要时才将响应解析为xml，但到那时调用调解员关闭了连接。

以下是一个示例序列：

<call blocking="true">
  <endpoint>
    <http uri-template="https://myserver.com/generatePDF?id=1234" method="GET"/>
  </endpoint>
</call>

<log level="custom">
  <property name="msg" value="Complete"/>
</log>

<log level="custom">
  <property name="body" expression="$body"/>
</log>

<log level="full"/>

观察日志，进行呼叫并等待响应。一旦响应完成，＆＃34;完成＆＃34;打印日志消息。但是当它试图访问$ body时会发生以下错误：

[2016-05-19 13:03:21,582]  INFO - LogMediator msg = Complete
[2016-05-19 13:03:21,584] ERROR - SequenceMediator Error reading data handler
org.apache.axiom.om.OMException: Error reading data handler
    at org.apache.axiom.om.impl.llom.OMTextImpl.internalSerialize(OMTextImpl.java:421)
    at org.apache.axiom.om.impl.util.OMSerializerUtil.serializeChildren(OMSerializerUtil.java:555)
    at org.apache.axiom.om.impl.llom.OMElementImpl.internalSerialize(OMElementImpl.java:875)
    at org.apache.axiom.om.impl.util.OMSerializerUtil.serializeChildren(OMSerializerUtil.java:555)
    at org.apache.axiom.om.impl.llom.OMElementImpl.internalSerialize(OMElementImpl.java:875)
    at org.apache.axiom.om.impl.llom.OMSerializableImpl.serialize(OMSerializableImpl.java:125)
    at org.apache.axiom.om.impl.llom.OMSerializableImpl.serialize(OMSerializableImpl.java:113)
    at org.apache.axiom.om.impl.llom.OMElementImpl.toString(OMElementImpl.java:988)
    at org.apache.synapse.util.xpath.SynapseXPath.stringValueOf(SynapseXPath.java:321)
    at org.apache.synapse.mediators.MediatorProperty.getEvaluatedExpression(MediatorProperty.java:138)
    at org.apache.synapse.mediators.builtin.LogMediator.setCustomProperties(LogMediator.java:216)
    at org.apache.synapse.mediators.builtin.LogMediator.getCustomLogMessage(LogMediator.java:139)
    at org.apache.synapse.mediators.builtin.LogMediator.getLogMessage(LogMediator.java:125)
    at org.apache.synapse.mediators.builtin.LogMediator.mediate(LogMediator.java:95)
    at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:81)
    at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:48)
    at org.apache.synapse.mediators.base.SequenceMediator.mediate(SequenceMediator.java:149)
    at org.apache.synapse.core.axis2.ProxyServiceMessageReceiver.receive(ProxyServiceMessageReceiver.java:185)
    at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:180)
    at org.apache.synapse.transport.passthru.ServerWorker.processEntityEnclosingRequest(ServerWorker.java:395)
    at org.apache.synapse.transport.passthru.ServerWorker.run(ServerWorker.java:142)
    at org.apache.axis2.transport.base.threads.NativeWorkerPool$1.run(NativeWorkerPool.java:172)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.io.IOException: Attempted read on closed stream.
    at org.apache.commons.httpclient.AutoCloseInputStream.isReadAllowed(AutoCloseInputStream.java:183)
    at org.apache.commons.httpclient.AutoCloseInputStream.read(AutoCloseInputStream.java:107)
    at java.util.zip.InflaterInputStream.fill(InflaterInputStream.java:238)
    at java.util.zip.InflaterInputStream.read(InflaterInputStream.java:158)
    at java.util.zip.GZIPInputStream.read(GZIPInputStream.java:116)
    at java.io.FilterInputStream.read(FilterInputStream.java:107)
    at org.wso2.carbon.relay.BinaryRelayBuilder.readAllFromInputSteam(BinaryRelayBuilder.java:39)
    at org.wso2.carbon.relay.StreamingOnRequestDataSource.getInputStream(StreamingOnRequestDataSource.java:59)
    at javax.activation.DataHandler.writeTo(DataHandler.java:305)
    at org.apache.axiom.util.stax.XMLStreamWriterUtils.writeBase64(XMLStreamWriterUtils.java:62)
    at org.apache.axiom.util.stax.XMLStreamWriterUtils.writeDataHandler(XMLStreamWriterUtils.java:138)
    at org.apache.axiom.om.impl.llom.OMTextImpl.internalSerialize(OMTextImpl.java:418)
    ... 24 more

单步执行代码我可以看到响应在http连接上可用。输入流是围绕该连接构建的，但在调用完成后，将在清理方法中关闭HTTP连接。

首次访问正文时，会读取流，但此时它已经关闭，这会产生以下错误。

如何使用带有阻止=＆＃34;的真实＆＃34;？

的呼叫中介来检索PDF

详细信息

WSO2 ESB 4.9.0

将以下内容添加到axis2_blocking_client.xml

的消息构建器部分

<messageBuilder contentType="application/pdf" class="org.wso2.carbon.relay.BinaryRelayBuilder" />

Answer 1

二进制中继使用这些格式化程序和构建程序通过Apache Synapse中继消息（包括格式良好和消息不良），而无需处理（例如，XML验证或处理）这些消息。二进制中继包括Builder和Formatter。收到消息后，Builder会创建一个伪SOAP消息，将传入的SOAP消息的内容作为二进制XML节点附加，并通过Apache Axis2内核发送，并在发送时，二进制中继格式化程序扩展SOAP消息并将附加内容写入输出通道。因此，消息通过Apache Synapse而不处理其内容，因为消息是在字节级别处理的，甚至非XML消息也可能通过Apache Synapse。

如需了解更多信息，请read。

如何让BinaryRelayBuilder阻止调用？

详细信息

1 个答案: